Electric furnace



' July 28, 1925.

E.L.SMALLEY ELECTRIC FURNACE Filed Aug, 11. 2 3 SheetsSheet 1 Jul 28, 192s E. L. SMALLEY ELECTRIC FURNACE Filed Aug. 11. 1922 3 Sheets-Sheet 2 July '28; I 925.

E. L. SMALLEY ELECTRIC FURNACE Filed Aug. ll.' 1922 3 Sheets-Sheet 5 Fur L ||||L1 heater units being broken Patented J ly 28, 1925.-

UNITED "STATES 1,547,623 PATIENT OFFICE.

v EDWIN L. SMALLEY, OF SOUTH ORANGE, JERSEY, ASSIGNOR TO ELECTRIC HEAT- IN G APPARATUS COMPANY, 01" NEWARK, NEW JERSEY.

ELECTRIC summon- Application filed August 11,1922. Serial No. 581,192.

To all whom it may concern:

Be it known that I, EDWIN L. SMALLEY, a citizen of the -United States, residing at South Orange, in the county of E ex and State of New Jersey, have 'invente certain new and useful Improvements in Electric Furnaces, of which the following is a clear and exact specification.

My invention relates to improvements in electrical furnaces and the same has for its object more particularly toprovide a furnace which is efficiently and. economically operated and in which the material to be heated may be readily conveyed to andiremoved therefrom. 1

, Further said invention has for its object to provide a furnace in which the bottom or base thereof is movable into and outv of the furnace'and in which the .heatingelements are automatically controlled by the r.

movement of said support or base.

means is provided'forretaining the resistor elements 1n place upon the furnace wall or support.-

elements thereof are protected against the accessofforeign matter or the'like thereto.

- .Other'features and advantages of myin'-- tion.

l 2 is a front-elevation thereof, partly in section. 1

Fig. 3 is a partial section, enlarged, taken on the line 33 of Fig. 1. v Fig. 4' is a partial, top view, enlarged, of

the car floor, the covering plates. for the away. Fig. 5 is a section on the line 5-5 of Fig. 4, and Fig. 6 is an enlarged, detail top View of a conductor rail and contact shoe.

In the furnace construction here re resented, let 1 indicate the, vertical me ers of its metallic frame, 2, 2", the longitudii nel members, and 3 the transverse members. The brick work, forming the walls 4 and top 5, is of any suitable character, The furnace interior, 6, is shown as open at its bottom, that is to say, while the furnace walls in the form of a car,

and top are of integral or continuous structure, the bottom thereof is movable, being composed of the bricks ing 7, having a metallic frame 8 and-mounted on wheels 9, that run on rails 10.

The heating units disposed along the walls 4 and top 5 are represented as resistors 11 carried by refractory plates 12, which are themselves supported by rails 13 that pro-- ject from the inner surfaces of said walls and top.

With electric furnaces of large size such as are comprehended by my invention for the heat treatment of large objects, especially where such objects have considerable length, it is desirable that the base portion .of the furnace, upon which the objects are to be supported, should be movable into and out of the housing. Therefore I have provided the car structure referred to, with wheels to run ona track that extends com- Further said invention has for its object pletely under the furnace and also extendsto provide a furnace in which improved beyond the furnace, so that the car can be ment outside the furnace, and then inoved into the furnace to form a constituent part Further said inventionhasfor its objectto. provide a' furnace in whichthe heating.

thereof. When the objects upon the car havereceived their heat treatment the car can be withdrawn from the furnace.

' It is desirable, in an electric furnace, that ygzes floor, as well as its sides and top, should 7 provided with sources of heat, so that the heating zone may extend clear around the furnace interior.

To meet this requirement I have devised themovable furnace bottom, herein represented, with furnacebricking, resistor elements 14 disposed thereon, and spacers 15,

the latter as examples of means for maintaining the alignment of the resistor lengths. thus preventing distortion thereof and possible short circuiting.

.- I have also found it desirable 'to institute automatic means for energizing the resistor complete heatin may depend; so ely ,upon its being'n'loved sisters 14; inthe mere act of moving the car bottom-into the furnace. Therefore, as will be apprehended, the

movable furnace bottom forming apart of my invention, in eifect itself constitutes. a unit whose functmmng into the furnace, and which becomes de-enfergized' as soon as it is withdrawn therefrom; all without the expenditure of time and labor in adjusting or releasing electrical connections.

The metallic frame of the car structure is shown as having secured thereto, at its opposite sides, longitudinal angle 'members 20 that com rise trou hjs to contain sand, and pendent anges 21v t jatiextend from the metallic framework of the furnace are adapted to enter these troughs when the car is moved into-the furnace, to thereby form sand seals,

thus'preventing the escape of furnace heat.

It will benoted, particularly by referring to Figs. 2 and 3, that the top of the bricking walls of the receptacle and disposed between successive strands or portions of said elements at points between the successive bends thereof to' maintain said strands in spaced relation, said blocks beingprovided with grooves or recesses 23 thereinreeeiving adjacent portions 'ofsaid element and permitting the blocks to extend over the strandsto hold the same against the substantially smooth unbroken surface of the bottom on" which the element is disposed.

By the use of these spacer blocks the resistors are retained intheir set v positions without the interposition of continuous-insulation between the resistor lengths, and thus an open heat field isprovided in the-hori -zontal plane of the resistors which I highly conducive to thermal-efficiency;

Practice has proven that the absence of separating material between the adjacent lengths or. resistor, thereby leaving the lateral plane occupied by the resistor ele-" ment otherwise entirely clear or free, has'the efiect of permitting more rapid heat release to the'furnace interior.

The element '14 is protected; by covering means. colgposed of a plurality of members orplate's I j the walls of theicar [and supported' thereby,

fitting in recesses 25 formed in and theblocks 15. A closed jioint is provided betweenv adj acent edges" o plates to prevent access ofv forei or of dirt to-the elementsli.

the several material e means employed for this purpose consists in pro bend ne I I yiding each plate with'an upwardly facing groove 26 along one'edge and with a down- .wardly extending flange 27 along the opposite-edge of the same, the flange 27 of one plate fitting into the groove 26 of the adjacent, plate, whereby the plates "are. interengaged or overlapped and a closed joint is provided. The plates or covers 24 serve as a support or top on which the material to be heated is placed for entry into the furnace.

' Variations within the spirit and scope of my-invention are equally comprehended by y the foregoing disclosure.

I claim 4 1. An electric furnace comprising a top portion, a base portion constituting a movable support for conveying the material to be heated, a heating element carried by said base portion, and means for energizing said heating element, substantially as specified. 2. An electric furnace comprising a top portion, a base portion enclosing with said top portion the interior'space of said furnace, and constitutinga movable support for conveying the material to be heated, aheating elementcarried by said base portion, and means for energizing said heating element, substantially as s ecified,

3'. An electric? urnace comprising a re 'fractory top portion, a refractory base portion enclosing with said top portion the'in- .terior space of said furnace, andconstituting a movable support for conveying the mate rial to be heated, a heating element carried Y by said base portion, means for-energizing said heating element, and a 'cover for said heating element directly exposed to the heat thereof and serving to support the material to be heated, substantially as specified.

4. Anelectric furnace comprising a top portion, a base portion constituting a movable sup ort for conve'ying the material to be heate a return-bend resistor element disposed horizontally upon said base portion, and a cover for said resistor element directly exposed to the heat thereof and serving to support the material to be heated, substantially as s ecified.

5. An e ectric furnace comprising a refractory top portion, a refractory base por surface of said base portion, means. for energizin said resistor element, and "a cover .forsai resistorelement directly exposed to thefheat thereofand serving to support the material" to be heated, substantially as specified.

'6. An electric furnace comprising a refractory top. portion, a refractory base'portion constituting a movablejsupport for conveying the material to be heated, a prerefractory means'interposed at intervals beh tween the strands of saidresistor element for maintaining the same in position on said base portion, a cover forsaid resistor ele- 'ment 'directly exposed-to the head thereof mg. said resistor andservin to support the-"material to be heated j'an j'meansf for-energizing said resistorfaeie'ment,substantially as specified.

7. electric.ffu'rnace comprising a refractory-:topportiom arefractory base por-' tion enclosing with-said base portion the intenor space .of said-furnace, and constituting a movable s'upportfor conveyingthe material to be heated, in return-hen resistor element disposed horizontally upon said base portion, refractory means interposed at intervals between the strands of said resistor element for maintaining the same in position, a'cover for said resistor element directly exposed to the heat thereof and servlng to su port the material to be heated, a resistor e ement in said furnace above'- the plane of said cover, and means for'energizelements, substantially as specified. 1 7 8.- The combination with an electric. furnace having a floor, of a resistorcom" d of endwise' connected, separated stran 10-" cated on said floor,.and spacers of relativw v lyshort len th disposed between adjacentv mice having a floor, of a resistor co r strands.

strands of t e resistor, thereby leaving a; heat zone clearance in the lateral plane of the resistor strands.

9.,The combination with an electric furof endwise connected, separated stran rated on :said floor, and spacer 'blocks of.

relatively short length disposed between adjacent resistor strands, the blocks. having undercut recesses for thelodgement of sai 10; The combination with an electric furnace havin'gfa floor, of a resistor com of endwise connected, separated stran s located on said floor, {spacers of relatively short length disposed between adilwe'ntmorizont'al lane,a'nd fivided nt tliei sister strands thereby leaving "a eat I-zone clearance inlateral plane ofJthe'resistor length -and; covering plates for said res sis 1 v 7 'a ihorizontal suihoeya' .nesister .el out 7 disposed 1pon-' "said posed of a pluralityofinemberg'inithe adjacent ges of forming a closed joint between the same, substantia as specified.

12. An electric furnace a'niov able support conveying the] niaterillflto be" specified.

. into and out of furnace, eati' carried by said-support and movab e thereand a cover for said resistor element-coins?? .19; nineties new base said.-- 1Iraterial and movable therewith, and means for'energizing said heating means to stantiallyasspecified. 13. An electric furnace comprising a moveat said material-when said support is in ;operat1ve'posit on within said furnace, sub

able support conveying the material to. be 3 heated and. movable into and out 10f jsaid furnace, a resistor element carried b said of said heating means to energize and deenergize the same as said support is moved, 7 substantially as'specified, r

V 15. 'An electric furnace comprisin a suprt, movable into and out of said. rnace, ating means carried by said support, and automatic means for energizing sai heat ng means when said su port is moved into po- I sition within said urnaee,

specified, g .7

1 16. An electric furnace comprising a support for conveying the material to be heated and, movable into and out of saidfurnace,

a resistor element carried .by aid 'supports and movable therewith, iand -automatie meansfor energizing said, elements: said support is moved intosaid "furnace whereby to heat said material, substantially as 17. An electric furnaceiconiprising a wall, I

heating means thereon, a su portmovable means with, and automatic means controlled by v movementfof said support for energizing and de-euergizing certainof said heating means.- I 18. An electric furnace comprising a wall,:

heating means thereon,.a support for conve ing the materialbe heated'fand movabi e into 'and out of said furnace, and heating means carried by said support andmovable =therewith,--said several heating means i pgovidin'ga heating zone enclosing said ma- 1121- electriofurnaceicomprisirigla fise iteriii whensaidsupriortis inoperative pos n g iihinmattre s s; substantially as nflpnpmmbl, ihto and outof saidfuron said iliase portion for sup porting material tofbeheated, and heating imia'liszcarried by. said -i baseportion below heated andj'movable into and Iojutf;offaaidf'inovable intoand out ofsaid fumes. a top furnace, carried thereby roastin on saidbasc' portion for supporting the material to be heated, and a heating element carried by said base portion below said top,

whereby to permit of said material being subjected to the heat of said elements, substantially as specified.

21. An electric furnace comprising a wall,

heating elements upon the inner surface thereof, a car adapted to be moved into and out of said furnace, a top on said car for.

supporting the material to be heated, a resistor element mounted on said car below said top, and automatic means operable to energize said resister element when said car is moved into said furnace, substantially as specified.

22.- An electric furnace comprising a sup- 7 port of refractory material, a return-bend.

resistor element thereon including a plu rality of strands spaced from each other, and separate spacer blocks of refractory material interposed between said strands at,

- spaced points, substantially as specified. p

23. An electric furnace comprising a sup"- port of refractory material having a substantially smooth unbroken surface, a return bend-resistor element dis osed thereon and emboding a plurality 0 strands arranged in spaced relation, and spacin members of insulating material interpose at intervals between said strands for maintainposition upon. the surface of said support, su

specified.

ing the same duly in operative stantially as sistor element disposed thereon and em bodying a plurality of strands arranged in spaced relation, and means for retaining stantially as specified.

said element on said wall and for maintaining said strands in spaced relation, sub- 26. An electric furnace comprising asupport of refractory material forming a'shallow receptacle, a return-bend resistor element-disppsed in said receptacle and embodying a plurality of strands arranged in spaced relation, and a plurality of separate spacers of refractory material 1nserted'be-.

Y tween successive strands, substantially asspecified. 27. An

electric furnace comprising a support of refractory material forming a shallow receptacle, a return-bend resistor ele- "ment disposed in said .receptacle and embodying a plurality of strands arranged-in spaced relation, and spacers of refractory material interposed between said strands at points between successive bends thereof and between said element and the wall of said receptacle, substantially as specified.

28. An electric furnace comprising a wall of refractory material, a return-bend reg,- sistor element disposed-thereon andv em-i bodying a plurality of. strands arranged in spaced relation, and separate spacer blocks interposed between said strands, and extendin over the same to retain said element on sai wall, substantially as specified.

. 29. An electric furnace comprising'a support of refractory, material,'a return-bend resistor element disposed on said support and embodying strands arranged in spaced relation, se arate' spacer blocks arranged between. sa1 strands, and a cover disposed over said blocks and said elements and in I spaced relation to' said element, substantially as specified.

30. An electric furnace comprising a sup..- port of refractory.- material having a substantially smooth- :junbroke'n' surface, a re-' turn-bend resistor element-disposedon said surface and embodying a pluralityv 10fv strands in spaced relation, separate spacer blocks disposed between said strands, and a cover positioned over said blocks in spaced relation to said element, substantially as specified.

31, An electric furnace comprising a supportofrefractory material providing a shallow receptacle, a return-bend resistor elementdisposedin said rec'e tacle and embodying a plurality of stran s arranged in spaced relation, separate spacerblocks of refractory material interposed between adjacent strands of said element at points between said element and the wall of said receptacle, and a cover disposed over said blocks and said receptacle in s aced relation to saidelement, substantially as specielectric furnacecomprising a suping a closed joint betweenthe sameysub stantially as specified.

33. An electric furnacejcomprising a. support of refractory material, a resistor element disposed thereon, and a plurality of cover plates arranged over said element, said plates having interengaging adjacent. edges, substantially as specified. a 34. An electric furnace comprising-a sup port of refractory material, a resistor ele ment disposed thereon, and a pluralityof lates arranged over said element,

ates having overlapping adjacent 'bstantially as specified. p '1 electric furnace comprising a bottom of refractory material forming a shallow receptacle with a substantially smooth unbroken inner surface, a return-bend resistor element disposed within said receptacle upon said smooth surface thereof and embodying a plurality of strands arranged in spaced relation, separate spacer blocks of refractory material interposed between said element and the Wall of said receptacle for maintaining said strands in spaced relation, and a plurality of cover plates mounted on said bottom over said receptacle, said cover plates having overlapping adjacent edges and constituting a support, substantially as specified.

36. An electric furnace comprising a support having a recess therein, a return-bend resistor element disposed in said recess, and

disposed at intervals between said strands for maintaining the same duly in operative position, substantially as specified.

37. An electric furnace comprising a support having a recess therein, a return-bend resistor element disposed in said recess, and embodying a plurality of strands arranged in spaced relation, refactory means disposed at intervals between said strands, and a cover for said resistor element directly exposed to the heat thereof, substantially as specified.

Signed at the borough of Manhattan in i the city, county and State of New York, this 10th day of August, 1922.

EDWIN L. SMALLEY. 

